Effect of image acquisition parameters on the radiopacity of bulk-fill and nanocomposite resins.

OBJECTIVE: This study evaluated the radiopacity of 2 bulk-fill resins (SonicFill and Filtek Bulk Fill) and a nanocomposite (Filtek Z350 XT) resin compared with enamel, dentin, and aluminum as measured with different exposure parameters. STUDY DESIGN: Resin disks were radiographed together with a 1-mm human tooth section and an aluminum stepwedge, at exposure times of 0.2 and 0.32 s, and source-image (S-I) distances of 30 and 40 cm, using complementary metal oxide semiconductor (CMOS) and photostimulable phosphor systems. Grayscale values were measured using ImageJ software. Paired Student t tests were used to compare the effect of the receptor on grayscale values for each material. Analysis of variance was used to evaluate the effects of receptor, exposure parameters, and the resins on radiopacity. RESULTS: All resins exhibited greater radiopacity scores than enamel and were significantly different from each other. Filtek Z350 produced the lowest radiopacity values, whereas SonicFill produced the highest. The radiopacity values were higher on images acquired with CMOS receptors. Receptor type, exposure time, S-I distance, and material, as well as many interactions of these parameters, affected the radiopacity of the resins. CONCLUSION: The tested resins complied with ISO 4049. Exposure parameters and digital receptors affected their radiopacity.

CBCT Performance and Endodontic Sealer Influence in the Diagnosis of Vertical Root Fractures.

AIM: To evaluate the performance of three cone beam computed tomography (CBCT) machines in detecting vertical root fractures (VRFs) in teeth filled with different sealers. MATERIALS AND METHODS: A total of 80 single-rooted premolars were subjected to instrumentation and restoration with gutta-percha + AH Plus sealer, gutta-percha + sealer 26, gutta-percha + fill canal, and gutta-percha without sealer as the control. Half of the samples were randomly subjected to root fracture and all the teeth were scanned by i-CAT (Imaging Sciences International, Hatfield, USA), PreXion (PreXion Inc., San Mateo, USA), and OrthoPhos XG (Sirona Dental System, Bensheim, Germany). Three examiners analyzed the images for the presence of fractures. RESULTS: The highest accuracy was obtained with the PreXion device, with Az = 0.85, while the i-CAT device provided higher sensitivity (0.93). The specificity values observed ranged between 0.75 and 0.70. Chi-squared tests (p > 0.05) demonstrated that the sealers did not exert a significant influence on the diagnosis of VRF. CONCLUSION: It may be concluded that endodontic sealers do not influence the detection of VRF. The PreXion device was the most accurate, having the highest specificity value. CLINICAL SIGNIFICANCE: Radiopaque materials might affect the diagnosis of VRFs because they can simulate fracture lines, leading to false-positive results. Moreover, CBCT machines present different specificities that could exert some influence on that.

Evaluation of Incidental Findings on Cone Beam Computed Tomography

Objective: To assess the prevalence of incidental findings in relation to the side of a patient's face, location, and age group on cone beam computed tomography. Material and Methods: 175 CBCT examinations were performed on patients aged between 12 and 77 years, consisting of recordings of the anatomical location and findings following each examination. For standardization of tomographic evaluations, acquired images were analyzed by two previously trained expert radiologists. After positional adjustment of the multi-dimensional images on the monitor screen, examination of each scan was conducted simultaneously on the coronal, axial, and sagittal planes. Fisher's exact tests and Chi-square tests were used to compare the frequencies of incidental findings using a significance level of 0.05. Results: The most frequent incidental finding was maxillary sinus mucosal thickening, which occurred on the right and left side in 46.3% and 46.9% of the patients, respectively. The second most frequent incidental finding was flattening of the mandibular condyle, occurring on the right and left side in 29.7% and 24% of the patients, respectively. No significant difference was observed among the individual age groups. The number of incidental findings per patient varied from 0 to 5 on the right side and left side and from 0 to 12 in total. The Kendall correlation coefficient for the number of incidental findings between the sides was 0.25 (p<0.0001), indicating a weak but significant and positive association between the sides in relation to the number of incidental findings. The mean total number of incidental findings was 4.07. Conclusion: The prevalence of the individual incidental findings and the total number of findings were not statistically different. However, some alterations were more likely to be observed bilaterally.

Mandible condyle osteochondroma: clinical case report / Osteocondroma do côndilo da mandíbula: relato de caso clínico

ABSTRACT Osteochondroma is one of the most common benign bone tumours. However, it a rare in the mandibular condyle. Depending on the symptoms and duration of the osteochondroma, the management ranges from excision of the tumor alone to condylectomy along with tumor excision. This paper presents a case of Osteochondroma after surgical treatment affecting the mandible of a 39-year-old man and highlights the diagnosis, surgical procedures and 3-year follow-up period. At the clinical examination, the patient presented severe mandibular lateral deviation to the right, left side disocclusion with a slight oral opening limitation, dental abrasion compatible with bruxism and class III. After 3-year follow-up 3 years later revealed that the surgical management posed was successful for Osteochondroma and the patient is currently under regular review.

RESUMO Osteocondroma é um dos tumores ósseos mais comuns, mas raramente acomete o côndilo mandibular. Dependendo dos sintomas e duração do Osteocondroma o manejo da lesão pode variar desde a excisão do tumor até a realização da condilectomia com a remoção do tumor. O objetivo deste trabalho é relatar um caso clínico de Osteocondroma acometendo o côndilo da mandíbula em um paciente de 39 anos de idade, ressaltando as etapas para a realização do diagnóstico, procedimentos cirúrgicos e follow-up de 3 anos. Ao exame clínico observou-se severo desvio mandibular para o lado direito, desoclusão do lado esquerdo, abertura de boca reduzida, abrasão dentária compatível com bruxismo e classe III. Após a realização de tratamento cirúrgico e o período de acompanhamento de 3 anos foi possível observar a resolução do caso em imagens de tomografia computadorizada de feixe cônico. Conclusão: Pode-se concluir que a terapia proposta resultou em sucesso e o paciente continua em acompanhamento periódico.

Intraobserver and interobserver reproducibility in linear measurements on axial images obtained by cone-beam computed tomography.

PURPOSE: This study was performed to investigate the intra- and inter-observer variability in linear measurements with axial images obtained by PreXion (PreXion Inc., San Mateo, USA) and i-CAT (Imaging Sciences International, Xoran Technologies Inc., Hatfield, USA) CBCT scanners, with different voxel sizes. MATERIALS AND METHODS: A cylindrical object made from nylon with radiopaque markers (phantom) was scanned by i-CAT and PreXion 3D devices. For each axial image, measurements were taken twice in the horizontal (distance A-B) and vertical (distance C-D) directions, randomly, with a one-week interval between measurements, by four oral radiologists with five years or more experience in the use of these measuring tools. RESULTS: All of the obtained linear measurements had lower values than those of the phantom. The statistical analysis showed high intra- and inter-observer reliability (p=0.297). Compared to the real measurements, the measurements obtained using the i-CAT device and PreXion tomography, on average, revealed absolute errors ranging from 0.22 to 0.59 mm and from 0.23 to 0.63 mm, respectively. CONCLUSION: It can be concluded that both scanners are accurate, although the linear measurements are underestimations, with no significant differences between the evaluators.

Evaluation of Root Fracture in endodontically treated Teeth using Cone Beam Computed Tomography.

AIM: Our objective was to perform an in vitro evaluation of root fracture in endodontically treated teeth using two cone beam computed tomography (CBCT) machines. MATERIALS AND METHODS: The sample comprised 86 single-rooted human premolars that had been fractured by a universal testing machine. The tomographic images were acquired using an Orthopantomograph OP300® and an Orthophos XG 3D® and evaluated by three examiners, by means of specific software. The teeth were classified into presence or absence of root fracture, then the root third where the fracture occurred, was determined. With regard to the detection of the fracture, the Kappa statistic was used for intra and interexaminer repro-ducibility at two distinct points in time. Chi-squared test was employed to analyze the sensitivity and specificity of the two tomographs (p < 0.05). RESULTS: The results showed a good or excellent Kappa index between examiners. As for the absolute frequency, the sensitivity (0.6) of the Orthophos XG 3D® equipment was superior, while specificity (0.91) was higher with the Orthopantomograph OP300®. On the receiver operating characteristics curve, moderate performance was found with an accuracy of 0.73 (OrthopantomographOP300®) and 0.74 (Orthophos XG 3D®) respectively. As far as the location of the root fracture is concerned, moderate agreement was verified using the Kappa statistic (k = 0.56). CONCLUSION: Although the regular CBCTs represent the imaging examination of choice for assisting root fracture diagnosis in endodontically treated teeth, their performance in this study demonstrated an imprecise diagnosis of fractures in a good many cases, irrespective of the tomography machine used. CLINICAL SIGNIFICANCE: An early and precise detection of root fractures is of the utmost clinical importance, but the radiopaque and/or metallic filling materials in the CBCT viewing field may generate artifacts, known as the beam-hardening effect, which could compromise root fracture detection.

Research on calcifications in the cervical region using panoramic and teleradiographic techniques / Calcificações na região cervical utilizando radiografias panorâmicas e telerradiografias

ABSTRACT Objective: The aim of the study was to evaluate the contribution of lateral and frontal teleradiographs to the identification and location of calcifications in soft tissues, when compared with those observed in panoramic radiographs. Methods: Radiopaque references in gutta-percha were placed unilaterally on the heads of three cadavers, endeavoring at all times to keep to the same level as the bifurcation of the common carotid artery in different structures, sites of possible calcifications, and three radiographic incidences were obtained for each anatomic part. Thus, the sample of this study was composed of 27 panoramic radiographs, 27 lateral teleradiographs and 27 frontal teleradiographs, totaling 81 radiographs. Results: According to the criteria of Cicchetti and Sparrow, the intraclass correlation coefficients (ICCs) obtained were below 0.40. Conclusion: It can be concluded that the lateral and frontal teleradiographs did not contribute efficiently to the identification and location of radiopacities in the cervical region, and that the anatomic conformation interferes in the observation of the presence of radiopacity in the cervical region.

RESUMO Objetivo: Avaliar a contribuição das telerradiografias, nas normas lateral e frontal, na identificação e localização de calcificações em tecidos moles, quando comparado com as observadas em radiografia panorâmica. Métodos: Referências opacas em guta percha foram posicionadas unilateralmente, em três cabeças de cadáveres, procurando manter sempre no mesmo nível da bifurcação da artéria carótida comum, em diferentes estruturas, sítios de possíveis calcificações e foram obtidas três incidências radiográficas para cada peça anatômica. Assim, a amostra deste estudo foi composta por 27 radiografias panorâmicas, 27 telerradiografias em norma lateral e 27 telerradiografias em norma frontal, totalizando 81 radiografias. Resultados: De acordo com os critérios de Cicchetti e Sparrow observou-se valores inferiores a 0,40 de coeficiente de correlação intraclasse (CCI) entre os métodos. Conclusão: Foi possível concluir que as telerradiografias em norma lateral e frontal não contribuem eficazmente na identificação e localização de radiopacidades na região cervical, e que a conformação anatômica interfere na observação da presença de radiopacidade na região cervical.

Radiopacity of 28 Composite Resins for Teeth Restorations.

AIM: Radiopacity is a fundamental requisite to check marginal adaptation of restorations. Our objective was to assess the radiopacity of 28 brands of light-cured composite resins and compare their radiopacity with that of enamel, dentin, and aluminum of equivalent thickness. MATERIALS AND METHODS: Composite resin disks (0.2, 0.5, and 1 mm) were radiographed by the digital method, together with an aluminum penetrometer and a human tooth equivalent tooth section. The degree of radiopacity of each image was quantified using digital image processing. Wilcoxon nonparametric test was used for comparison of the mean thickness of each material. RESULTS: All of the materials tested had an equal or greater radiopacity than that of aluminum of equivalent thickness. Similar results for enamel were found with the exception of Durafill, which was less radiopaque than enamel (p < 0.05). All the specimens were more radiopaque than dentin, except for P90 (which was equally radiopaque) and Durafill (which was less radiopaque). The thickness of the specimens may influence the similarity to the enamel's radiopacity. All of the composite resins comply with specification #27 of the American Dental Association. The radiopacity of Amelogen Plus, Aph, Brilhiante, Charisma, Concept Advanced, Evolux X, Exthet X, Inten S, Llis, Master Fill, Natural Look, Opallis, P60, Tetric, Tph, Z100, and Z250 was significantly higher than that of enamel (p < 0.05). CONCLUSION: With these composites, it is possible to observe the boundaries between restoration and tooth structure, thus allowing clinicians to establish the presence of microleakage or restoration gap. CLINICAL SIGNIFICANCE: Suitable radiopacity is an essential requisite for good-quality esthetic restorative materials. We demonstrate that only some composites have the sufficient radiopacity to observe the boundaries between restoration and tooth structure, which is the main cause of restoration failure.

Perception of professionals in the assessment of coronoid hyperplasia by computed tomography.

Coronoid Hyperplasia (CH) is a non-neoplastic and relatively rare enlargement of the coronoid process that may limit mandibular movement as a consequence of the close association between the hyperplastic coronoid process and the anterior region of the zygomatic bone. Computed tomography (CT) is extremely useful for the observation of this association and plays an important role in diagnosing and planning surgical treatment. Once the CT scan is performed, the data can be viewed in many different arrangements, including multiplanar (MPR) and 3D rendering, although the resolution of the latter may not be as good as that of the former. Our aim is to analyze the importance of and preference for multiplanar and 3D reconstruction images for diagnosing and interpreting Coronoid Hyperplasia (CH), by comparing the opinions of oral surgeons and oral radiologists who analyzed both temporomandibular joints (TMJ) in 20 patients. Three images of each TMJ comprised the set of scans (MPR, 3D reconstructions with maximum intercuspation and 3D reconstructions with maximum mouth opening). After each analysis, the members of the two groups answered a questionnaire about the usefulness of each examination and classified the association between the head of mandible and mandibular fossa. Hypomotility was present in 55.2%. Both groups stated that both MPR and 3D reconstructions, particularly the latter, were fundamental for diagnosing CH and that they would request them in order to interpret CH correctly. The examiners were found to differ significantly regarding their opinion of MPR; only radiologists considered MPR to be less elucidative for the diagnosis of CH.

Perception of professionals in the assessment of coronoid hyperplasia by computed tomography

Coronoid Hyperplasia (CH) is a non-neoplastic and relatively rare enlargement of the coronoid process that may limit mandibular movement as a consequence of the close association between the hyperplastic coronoid process and the anterior region of the zygomatic bone. Computed tomography (CT) is extremely useful for the observation of this association and plays an important role in diagnosing and planning surgical treatment. Once the CT scan is performed, the data can be viewed in many different arrangements, including multiplanar (MPR) and 3D rendering, although the resolution of the latter may not be as good as that of the former. Our aim is to analyze the importance of and preference for multiplanar and 3D reconstruction images for diagnosing and interpreting Coronoid Hyperplasia (CH), by comparing the opinions of oral surgeons and oral radiologists who analyzed both temporomandibular joints (TMJ) in 20 patients. Three images of each TMJ comprised the set of scans (MPR, 3D reconstructions with maximum intercuspation and 3D reconstructions with maximum mouth opening). After each analysis, the members of the two groups answered a questionnaire about the usefulness of each examination and classified the association between the head of mandible and mandibular fossa. Hypomotility was present in 55.2%. Both groups stated that both MPR and 3D reconstructions, particularly the latter, were fundamental for diagnosing CH and that they would request them in order to interpret CH correctly. The examiners were found to differ significantly regarding their opinion of MPR; only radiologists considered MPR to be less elucidative for the diagnosis of CH.

A Hiperplasia Coronoide (HC) e um aumento nao-neoplasico e relativamente raro do processo coronoide que pode limitar o movimento mandibular, como consequencia da intima relacao entre o processo coronoide hiperplasico e a regiao anterior do osso zigomatico. A tomografia computadorizada (TC) e extremamente util para a observacao dessa relacao, desempenhando assim um papel importante no diagnostico e planejamento do tratamento cirurgico. Uma vez que a TC e realizada, os dados podem ser vistos em muitos arranjos diferentes, incluindo o multiplanar (MPR) e a reconstrucao em 3D, no entanto, a resolucao desta ultima pode nao ser tao boa quanto a primeira. Nosso objetivo e analisar a importancia e a preferencia por reconstrucoes de imagens multiplanares (MPR) e 3D para diagnosticar e interpretar a Hiperplasia Coronoide (HC), comparando cirurgioes buco-maxilo-faciais com radiologistas orais. Ambas as articulacoes temporomandibulares (ATM) de 20 pacientes foram analisadas pelos 2 grupos. Tres imagens de cada ATM compreenderam o conjunto de exames (MPR, reconstrucoes 3D em maxima intercuspidacao e reconstrucoes 3D com abertura maxima da boca). Apos cada analise, os grupos responderam a um questionario sobre a utilidade de cada exame e classificou a relacao entre a cabeca da mandibula e da fossa mandibular. A Hipomobilidade esteve presente em 55,2%. Ambos os grupos afirmaram que tanto MPR e as reconstrucoes em 3D, especialmente a ultima, foram fundamentais para diagnosticar CH e as requisitariam para interpretar a HC corretamente. Foi encontrada uma diferenca significativa entre os examinadores sobre a MPR; apenas o grupo de radiologistas considerou que este exame nao e tao elucidativo para o diagnostico da CH.

Craniofacial features of operated unilateral complete cleft lip and palate children: a case control study / Crescimento maxilo-mandibular em crianças com fissura unilateral completa de lábio e palato reparada: estudo caso controle

OBJECTIVE: To compare the craniofacial features of Brazilian children who had received surgery for unilateral complete cleft lip and palate compared with non-cleft group. METHODS: Craniofacial features were evaluated on lateral cephalometric radiographs. 46 patients with unilateral complete cleft lip and palate were divided by gender and matched at ages 6, 7, 8 and 9. They were compared with 46 non-cleft children, equally divided by gender and matched the same age groups. All comparisons were carried out by means of the Angles SNA, SNB and ANB. The findings were analyzed on the basis of the two-way Analysis of Variance (ANOVA) with p <0.05 significance level. RESULTS: Both the angle SNA and SNB in the cleft group had a lower average in both genders and all age groups compared with the non-cleft group (p<0.0001). The average values of ANB were significantly higher in the cleft group (p<0.05) both in males and females and in all age groups studied. CONCLUSION: Children who had received surgery for unilateral complete cleft lip and palate during childhood had maxillary and mandibular retrusion and a class II skeletal pattern in relation to non-cleft group. .

OBJETIVO: Comparar o crescimento ântero-posterior da maxila e da mandíbula entre pacientes com fissura unilateral completa de lábio e palato reparada e pacientes que não apresentavam nenhuma alteração craniofacial. MÉTODOS: Foram selecionadas 46 telerradiografias cefalométricas em norma lateral de pacientes com fissura unilateral completa de lábio e palato que foram submetidos às cirurgias primárias de correção durante a infância (grupo de estudo). A amostra do grupo controle foi composta por 46 telerradiografias cefalométricas em norma lateral de pacientes sem nenhuma alteração craniofacial e que apresentavam valores para os ângulos SNA e SNB dentro dos valores pré-estabelecidos de normalidade. O gênero e as faixas etárias entre 6 e 9 anos dos pacientes foram pareados e comparados em ambos os grupos. A comparação entre os dois grupos foi realizada por meio dos ângulos SNA, SNB e ANB. Aplicou-se a análise de variância (ANOVA), considerando-se o nível de significância de 5%. RESULTADOS: Observou-se diferença significativa entre os grupos de pacientes com fissura reparada e controle (p<0,0001), ou seja, o grupo com fissura reparada apresentou menor média de SNA e SNB em todas as idades. Para o ângulo ANB, o grupo com fissura reparada apresentou maior média em todas as faixas etárias (p<0,05). CONCLUSÃO: Pode-se concluir que o grupo de pacientes com fissura unilateral completa de lábio e palato reparada nas faixas etárias estudadas e em ambos os gêneros apresentaram maxila e mandíbula retruídas em uma relação esquelética de Classe II em relação ao grupo controle. .

Assessment of the mandibular incisive canal by panoramic radiograph and cone-beam computed tomography.

Objectives. The region between mental foramens is considered as a zone of choice for implants. However, complications may arise due to an extension anterior to the mental foramen that forms the mandible incisive canal [MIC]. Our goal is to evaluate identification of MIC by both panoramic radiograph [PAN] and cone-beam computed tomography [CBCT]. Methods. 150 cases with bilateral MIC were analyzed. Images of a radiolucent canal, within the trabecular bone, surrounded by a radiopaque cortical bone representing the canal walls, and extending to the anterior portion beyond the mental foramen, were considered by two independent radiologists as being images of MIC. PAN and CBCT of these cases were evaluated by 2 other radiologists at different times. Agreement between results of examination methods was assessed by the Kappa coefficient. The interexaminer and intramethod rates for detection of MIC were analyzed by the McNemar test. Gender, mandible side, examiner, and type of method were analyzed by the generalized estimating equations [GEE] model. Results. significant difference between examiners [PAN: P = 0.146; CBCT: P = 0.749] was not observed. Analysis by GEE model showed no significant difference between genders [P = 0.411] and examiners [P = 0.183]. However, significant difference was observed for identification in both mandible right side [P = 0.001], where the identification frequency was higher, and CBCT method [P < 0.001]. Conclusions. PAN was not shown to be a safe examination to identify MIC. CBCT should always be used in preoperative planning and to reduce the number of complications in implant surgeries.

Osteoma em órbita / Orbital osteoma

O osteoma é uma tumefação benigna com crescimento lento, contínuo e apresenta-se como massa bem circunscrita, radiopaca, podendo ser lobulada. Caracteriza-se pela proliferação de osso cortical ou medular. A etiologia dessa lesão é desconhecida. Pode ser classificado em perióstico, central (endosteal) e extra-esqueletal. Clinicamente, é assintomático, mas pode produzir aumento de volume e assimetria facial. A tomografia computadorizada é o melhor exame de imagem para o diagnóstico. O tratamento é cirúrgico e somente indicado em pacientes com sintomas clínicos. Nossa proposta é apresentar um caso clínico em órbita cuja queixa era estética e de diplopia.

Osteoma is a benign tumor with continuous slow growing that appears as a well-circumscribed radiopaque mass that can be smooth or lobulated. It is characterized by proliferation of compact or medullar bone. Its etiology is unknown. It can be classified as periosteal, central or extra skeletal and, clinically, it is asymptomatic, but it can produce an increased volume, causing facial asymmetry. The computed tomography is the best image exam for this diagnosis. The treatment is surgical and only indicated to patients with clinical symptoms. Our purpose is to present a case report of a patient with aesthetic complaint and diplopia.

Desmistificando a apoptose no câncer bucal / Demystifying the apoptosis in oral cancer

O desenvolvimento do câncer está relacionado com alterações na estrutura do DNA e na regulação genética. Nos últimos anos, um importante avanço para a biologia molecular foi o melhor conhecimento sobre a participação dos genes no carcinoma espinocelular, o mais freqüente tumor maligno da cavidade oral. As principais classes de genes envolvidos no desenvolvimento das neoplasias malignas são os oncogenes e os genes supressores de tumor. O objetivo deste trabalho é fazer uma breve e objetiva revisão, voltada ao clínico geral, sobre a expressão de proteínas associadas à apoptose participantes na patogênese do câncer bucal.

Synovial chondromatosis of the temporomandibular joint: an asymptomatic case report and literature review.

Synovial chondromatosis of the temporomandibular joint (TMJ) is a rare lesion characterized by the presence of loose bodies in the glenoid fossa. Swelling, unilateral pain, occlusal changes, clicking, crepitation, deviation, and limited mandibular function are the most common characteristics, although this combination is not always apparent. Radiopacities of the TMJ should be thoroughly investigated as some signals and symptoms may be not present or combined, taking months or even years to confirm a diagnosis. A case report is presented here with a brief literature review, where surgical removal was the therapy of choice, calling attention to the absence of symptoms and some signals, which may mislead final diagnosis.

Estudo comparativo da densidade radiográfica de cimentos resinosos / Comparative study of the radiographic density of resinous cements

Introdução: A radiopacidade dos cimentos resinosos revela a presença de partículas densas, sendo útil na identificação da adaptação de peças cimentadas. Nosso objetivo é comparar a densidade óptica de diferentes cimentos resinosos pelos métodos radiográficos convencional e digital. Métodos: Para cada cimento escolhido (C&B, BisCem, Enforce) e para o grupo-controle (amálgama) foram confeccionados 5 corpos de prova (cp) idênticos em uma matriz de pvc. Cada um dos cp foi radiografado 3 vezes tanto pelo método convencional (utilizando-se filme periapical e aparelho de raios X intra-oral), quanto pelo digital (utilizando-se placas sensoras periapicais do sistema Digora-Soredex). As radiografias convencionais foram digitalizadas e a análise óptica da densidade dos materiais foi comparada pelo software Image J (NIH Image - Machintoch). Para o tratamento estatístico realizado pela ANOVA com 2 fatores e o teste complementar de Tukey com nível de significância de 5%, os valores considerados foram os obtidos a partir da média dos valores entre as diferentes radiografias e cp. Resultados: os valores de densidade pelo método convencional e digital foram respectivamente para cada material: 232,87 e 255 para o amálgama; 136,73 e 136,24 para o Enforce; 135,44 e 148,51 para o Bis-Cem e 125,24 e 58,97 para o C&B. Conclusões: Não houve diferenças significantes entre os métodos radiográficos (p=0,069%). Foram verificadas diferenças significantes entre os materiais (p=0,00), em ambos os métodos, exceto entre o Enforce e o BisCem, que obtiveram média de tons de cinza semelhantes. O cimento C&B mostrou as menores médias de tons de cinza.

Introduction: The radiopacity of the resinous cements reveals the presence of thick particles that are useful on observation of restorative adaptation. The aim of this study is to compare the optical density of different resinous cements, by using the conventional and the digital radiography. Methods: 5 samples (cp) of each resinous cements (C&B, BisCem, Enforce) and for amalgam were identically built on a matrix of pvc. Each cp was radiographed 3 times both by the conventional method (using periapical film, as well as an intra-oral x-ray machine) and by the digital method (using periapical phosphor sensors plates of the Digora Systems, Soredex). The conventional radiographies were digitalized and the optical density of the studied materials was compared using the Image J software (NIH Image - Machintoch). ANOVA with 2 factors and Tukey test with level of significance of 5% were used for statistical analysis and the considered values were those obtained from the average value of the different radiographies and cp. Results: The density values for the conventional and digital methods were, respectively, for each material: 232,87 and 255 for amalgam; 136,73 and 136,24 for Enforce; 135,44 and 148,51 for Bis-Cem and 125,24 and 58,97 for C&B. Conclusions: There were no significant differences between the radiographic methods (p=0,069%). Significant differences were found among the materials (p=0,00) in both methods, except for Enforce and for BisCem that presented similar histogram values. The cement C&B showed the lowest average values of gray tones.

Parameters in panoramic radiography for differentiation of radiolucent lesions.

OBJECTIVE: The aims of this study were to establish parameters in panoramic radiography for interpretation of unilocular radiolucent lesions, and to compare the accuracy of diagnoses given by examiners before and after using these parameters. MATERIAL AND METHODS: In Part I, 12 specialists analyzed 24 images and the diagnostic criteria used by each examiner to make correct diagnoses were used to build a list of basic radiographic parameters for each pathology (ameloblastoma, keratocystic odontogenic tumor, dentigerous cyst, and idiopathic bone cavity). In Part II, this list was used by 6 undergraduate students (Un), 8 recently graduated dentists (D), 3 oral pathologists, 3 stomatologists, 3 oral radiologists, and 3 oral surgeons to diagnose the corresponding pathologies in the other set of 24 panoramic radiographs (T2). The same analysis occurred without using this list (T1). The method of generalized estimating equations (GEE) was used in order to estimate the probability of making a correct diagnosis depending on the specialty of the examiner, type of lesion, and moment of the evaluation, T1 or T2 (before or after they had access to the list of parameters, respectively). RESULTS: Higher values were obtained for the probability (GEE) of making a correct diagnosis on T2; the group Un presented the highest improvement (14.6 %); no differences between the probabilities were observed either between Un and D, or among the different groups of specialists. CONCLUSIONS: The use of panoramic radiographic parameters did allow improving the diagnostic accuracy for all groups of examiners.

Radiographic interpretation of unilocular radiolucent mandibular lesions.

The main goal of this study was to identify the main distinctive radiographic characteristics of different unilocular radiolucent mandibular lesions based on the criteria used by different groups of specialists during the process of radiograph interpretation to arrive at a correct diagnosis. A total of 24 panoramic radiographs were selected exhibiting the following lesions: ameloblastoma, keratocystic odontogenic tumor, dentigerous cyst and simple bone cyst. Six cases of each pathology were analyzed by 3 specialists from 4 related areas (pathologists, stomatologists, radiologists and oral surgeons). A number of important distinctive features and confounding characteristics that are liable to misinterpretation were pointed out by the specialists during the analysis. The method of generalized estimating equations (GEE) was used to estimate the probability of correct diagnosis according to the specialization of the examiner and the type of lesion and no significant relation was found (p>0.05 for all variables). The overall percentage of correct diagnosis among the specialists was around 56%, which shows that these lesions are of difficult radiographic diagnosis. Although the specialty of the examiners did not influence the results, i.e., the 4 different kinds of specialists showed the same diagnostic capacity, the criteria used for interpreting the same lesions were often different among the specialists. The compilation of these criteria enabled the identification and selection of some useful distinctive radiographic characteristics to formulate diagnostic hypothesis of unilocular radiolucent lesions. The radiographic diagnosis of the unilocular radilucent mandibular lesions is particularly difficult and the histopathological examination is essential to make the definitive diagnosis.

Parameters in panoramic radiography for differentiation of radiolucent lesions

OBJECTIVE: The aims of this study were to establish parameters in panoramic radiography for interpretation of unilocular radiolucent lesions, and to compare the accuracy of diagnoses given by examiners before and after using these parameters. MATERIAL AND METHODS: In Part I, 12 specialists analyzed 24 images and the diagnostic criteria used by each examiner to make correct diagnoses were used to build a list of basic radiographic parameters for each pathology (ameloblastoma, keratocystic odontogenic tumor, dentigerous cyst, and idiopathic bone cavity). In Part II, this list was used by 6 undergraduate students (Un), 8 recently graduated dentists (D), 3 oral pathologists, 3 stomatologists, 3 oral radiologists, and 3 oral surgeons to diagnose the corresponding pathologies in the other set of 24 panoramic radiographs (T2). The same analysis occurred without using this list (T1). The method of generalized estimating equations (GEE) was used in order to estimate the probability of making a correct diagnosis depending on the specialty of the examiner, type of lesion, and moment of the evaluation, T1 or T2 (before or after they had access to the list of parameters, respectively). RESULTS: Higher values were obtained for the probability (GEE) of making a correct diagnosis on T2; the group Un presented the highest improvement (14.6 percent); no differences between the probabilities were observed either between Un and D, or among the different groups of specialists. CONCLUSIONS: The use of panoramic radiographic parameters did allow improving the diagnostic accuracy for all groups of examiners.

Multifocal diffuse oral melanoacanthoma: a case report.

Oral melanoacanthoma (OMA) is a rare benign lesion characterized by colonization of acanthotic epithelium by dendritic melanocytes. Although its pathogenenesis remains uncertain, its clinical behavior and spontaneous remission suggest a non-neoplastic nature. Clinically, it may present as a solitary or multifocal lesion; however these two variants exhibit different features. The clinical appearance of OMA is not pathognomonic and biopsy is mandatory. OMA requires no treatment or periodic observation. Here, we report a case of OMA with diffuse lesions also affecting the tongue in a 74-year-old black woman, whose diagnosis was based essentially on clinical and histological features. The immunohistochemical profile is also presented.